Research on the amphibian Xenopus has provided numerous new insights into cell and developmental biology. With their large size and abundance, they provide unparalleled material for biochemical and cell biological analysis of complex processes such as the cell cycle and chromosome mechanics. For embryological experiments, the embryos are readily manipulated by microsurgery and by microinjection can be subjected to gain or loss of gene function. In order to make Xenopus more useful for the modern age of "systems biology" where proteomic and genomic analyses promise a comprehensive understanding of life's processes, we propose here to complement the genome assembly of Xenopus tropicalis with a gene and protein level genome assembly for Xenopus laevis. The allotetraploid Xenopus laevis is in wider use than the smaller, diploid Xenopus tropicalis, because of its history, robustness, and the size and quantity of eggs that can be obtained for embryological and cell biological experiments. We propose to carry out high throughput sequencing of X. laevis, and generate a gene-scale assembly. By selecting regions complementary to the X. tropicalis sequence we will be able to assemble X. laevis genes from relatively inexpensive, short read data. The project provides some computational challenges that will need to be overcome and the approaches developed will be of wide utility in characterizing genomes of other organisms. We will provide support for genome annotation by Xenbase and deposit gene and protein collections in public databases to ensure that the resources are widely available. PUBLIC HEALTH RELEVANCE: Xenopus laevis eggs and embryos have been the material of choice for work on vertebrate experimental embryology and biochemical dissection of the cell cycle, providing insights into human biology. We propose to fill a large gap in the essential resources for this work, namely a catalogue of the gene and protein content.